Commit 33f0f88f authored by Alan Cox's avatar Alan Cox Committed by Linus Torvalds

[PATCH] TTY layer buffering revamp

The API and code have been through various bits of initial review by
serial driver people but they definitely need to live somewhere for a
while so the unconverted drivers can get knocked into shape, existing
drivers that have been updated can be better tuned and bugs whacked out.

This replaces the tty flip buffers with kmalloc objects in rings. In the
normal situation for an IRQ driven serial port at typical speeds the
behaviour is pretty much the same, two buffers end up allocated and the
kernel cycles between them as before.

When there are delays or at high speed we now behave far better as the
buffer pool can grow a bit rather than lose characters. This also means
that we can operate at higher speeds reliably.

For drivers that receive characters in blocks (DMA based, USB and
especially virtualisation) the layer allows a lot of driver specific
code that works around the tty layer with private secondary queues to be
removed. The IBM folks need this sort of layer, the smart serial port
people do, the virtualisers do (because a virtualised tty typically
operates at infinite speed rather than emulating 9600 baud).

Finally many drivers had invalid and unsafe attempts to avoid buffer
overflows by directly invoking tty methods extracted out of the innards
of work queue structs. These are no longer needed and all go away. That
fixes various random hangs with serial ports on overflow.

The other change in here is to optimise the receive_room path that is
used by some callers. It turns out that only one ldisc uses receive room
except asa constant and it updates it far far less than the value is
read. We thus make it a variable not a function call.

I expect the code to contain bugs due to the size alone but I'll be
watching and squashing them and feeding out new patches as it goes.

Because the buffers now dynamically expand you should only run out of
buffering when the kernel runs out of memory for real.  That means a lot of
the horrible hacks high performance drivers used to do just aren't needed any
more.

Description:

tty_insert_flip_char is an old API and continues to work as before, as does
tty_flip_buffer_push() [this is why many drivers dont need modification].  It
does now also return the number of chars inserted

There are also

tty_buffer_request_room(tty, len)

which asks for a buffer block of the length requested and returns the space
found.  This improves efficiency with hardware that knows how much to
transfer.

and tty_insert_flip_string_flags(tty, str, flags, len)

to insert a string of characters and flags

For a smart interface the usual code is

    len = tty_request_buffer_room(tty, amount_hardware_says);
    tty_insert_flip_string(tty, buffer_from_card, len);

More description!

At the moment tty buffers are attached directly to the tty.  This is causing a
lot of the problems related to tty layer locking, also problems at high speed
and also with bursty data (such as occurs in virtualised environments)

I'm working on ripping out the flip buffers and replacing them with a pool of
dynamically allocated buffers.  This allows both for old style "byte I/O"
devices and also helps virtualisation and smart devices where large blocks of
data suddenely materialise and need storing.

So far so good.  Lots of drivers reference tty->flip.*.  Several of them also
call directly and unsafely into function pointers it provides.  This will all
break.  Most drivers can use tty_insert_flip_char which can be kept as an API
but others need more.

At the moment I've added the following interfaces, if people think more will
be needed now is a good time to say

 int tty_buffer_request_room(tty, size)

Try and ensure at least size bytes are available, returns actual room (may be
zero).  At the moment it just uses the flipbuf space but that will change.
Repeated calls without characters being added are not cumulative.  (ie if you
call it with 1, 1, 1, and then 4 you'll have four characters of space.  The
other functions will also try and grow buffers in future but this will be a
more efficient way when you know block sizes.

 int tty_insert_flip_char(tty, ch, flag)

As before insert a character if there is room.  Now returns 1 for success, 0
for failure.

 int tty_insert_flip_string(tty, str, len)

Insert a block of non error characters.  Returns the number inserted.

 int tty_prepare_flip_string(tty, strptr, len)

Adjust the buffer to allow len characters to be added.  Returns a buffer
pointer in strptr and the length available.  This allows for hardware that
needs to use functions like insl or mencpy_fromio.
Signed-off-by: default avatarAlan Cox <alan@redhat.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: default avatarHirokazu Takata <takata@linux-m32r.org>
Signed-off-by: default avatarSerge Hallyn <serue@us.ibm.com>
Signed-off-by: default avatarJeff Dike <jdike@addtoit.com>
Signed-off-by: default avatarJohn Hawkes <hawkes@sgi.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: default avatarAdrian Bunk <bunk@stusta.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 6ed80991
......@@ -186,9 +186,6 @@ static void tty_receive_char(struct tty_struct *tty, char ch)
}
}
if((tty->flip.flag_buf_ptr == NULL) ||
(tty->flip.char_buf_ptr == NULL))
return;
tty_insert_flip_char(tty, ch, TTY_NORMAL);
}
......@@ -653,8 +650,7 @@ void chan_interrupt(struct list_head *chans, struct work_struct *task,
chan = list_entry(ele, struct chan, list);
if(!chan->input || (chan->ops->read == NULL)) continue;
do {
if((tty != NULL) &&
(tty->flip.count >= TTY_FLIPBUF_SIZE)){
if (tty && !tty_buffer_request_room(tty, 1)) {
schedule_delayed_work(task, 1);
goto out;
}
......
......@@ -279,6 +279,7 @@ static int hci_uart_tty_open(struct tty_struct *tty)
tty->disc_data = hu;
hu->tty = tty;
tty->receive_room = 65536;
spin_lock_init(&hu->rx_lock);
......@@ -348,20 +349,6 @@ static void hci_uart_tty_wakeup(struct tty_struct *tty)
hci_uart_tx_wakeup(hu);
}
/* hci_uart_tty_room()
*
* Callback function from tty driver. Return the amount of
* space left in the receiver's buffer to decide if remote
* transmitter is to be throttled.
*
* Arguments: tty pointer to associated tty instance data
* Return Value: number of bytes left in receive buffer
*/
static int hci_uart_tty_room (struct tty_struct *tty)
{
return 65536;
}
/* hci_uart_tty_receive()
*
* Called by tty low level driver when receive data is
......@@ -544,7 +531,6 @@ static int __init hci_uart_init(void)
hci_uart_ldisc.write = hci_uart_tty_write;
hci_uart_ldisc.ioctl = hci_uart_tty_ioctl;
hci_uart_ldisc.poll = hci_uart_tty_poll;
hci_uart_ldisc.receive_room = hci_uart_tty_room;
hci_uart_ldisc.receive_buf = hci_uart_tty_receive;
hci_uart_ldisc.write_wakeup = hci_uart_tty_wakeup;
hci_uart_ldisc.owner = THIS_MODULE;
......
......@@ -80,7 +80,7 @@ config SERIAL_NONSTANDARD
config COMPUTONE
tristate "Computone IntelliPort Plus serial support"
depends on SERIAL_NONSTANDARD && BROKEN_ON_SMP
depends on SERIAL_NONSTANDARD
---help---
This driver supports the entire family of Intelliport II/Plus
controllers with the exception of the MicroChannel controllers and
......@@ -153,7 +153,7 @@ config DIGIEPCA
config ESPSERIAL
tristate "Hayes ESP serial port support"
depends on SERIAL_NONSTANDARD && ISA && BROKEN_ON_SMP && ISA_DMA_API
depends on SERIAL_NONSTANDARD && ISA && ISA_DMA_API
help
This is a driver which supports Hayes ESP serial ports. Both single
port cards and multiport cards are supported. Make sure to read
......@@ -166,7 +166,7 @@ config ESPSERIAL
config MOXA_INTELLIO
tristate "Moxa Intellio support"
depends on SERIAL_NONSTANDARD && BROKEN_ON_SMP
depends on SERIAL_NONSTANDARD
help
Say Y here if you have a Moxa Intellio multiport serial card.
......
......@@ -265,8 +265,9 @@ static _INLINE_ void receive_chars(struct async_struct *info)
int status;
int serdatr;
struct tty_struct *tty = info->tty;
unsigned char ch;
unsigned char ch, flag;
struct async_icount *icount;
int oe = 0;
icount = &info->state->icount;
......@@ -282,15 +283,12 @@ static _INLINE_ void receive_chars(struct async_struct *info)
status |= UART_LSR_OE;
ch = serdatr & 0xff;
if (tty->flip.count >= TTY_FLIPBUF_SIZE)
goto ignore_char;
*tty->flip.char_buf_ptr = ch;
icount->rx++;
#ifdef SERIAL_DEBUG_INTR
printk("DR%02x:%02x...", ch, status);
#endif
*tty->flip.flag_buf_ptr = 0;
flag = TTY_NORMAL;
/*
* We don't handle parity or frame errors - but I have left
......@@ -319,7 +317,7 @@ static _INLINE_ void receive_chars(struct async_struct *info)
* should be ignored.
*/
if (status & info->ignore_status_mask)
goto ignore_char;
goto out;
status &= info->read_status_mask;
......@@ -327,33 +325,28 @@ static _INLINE_ void receive_chars(struct async_struct *info)
#ifdef SERIAL_DEBUG_INTR
printk("handling break....");
#endif
*tty->flip.flag_buf_ptr = TTY_BREAK;
flag = TTY_BREAK;
if (info->flags & ASYNC_SAK)
do_SAK(tty);
} else if (status & UART_LSR_PE)
*tty->flip.flag_buf_ptr = TTY_PARITY;
flag = TTY_PARITY;
else if (status & UART_LSR_FE)
*tty->flip.flag_buf_ptr = TTY_FRAME;
flag = TTY_FRAME;
if (status & UART_LSR_OE) {
/*
* Overrun is special, since it's
* reported immediately, and doesn't
* affect the current character
*/
if (tty->flip.count < TTY_FLIPBUF_SIZE) {
tty->flip.count++;
tty->flip.flag_buf_ptr++;
tty->flip.char_buf_ptr++;
*tty->flip.flag_buf_ptr = TTY_OVERRUN;
}
oe = 1;
}
}
tty->flip.flag_buf_ptr++;
tty->flip.char_buf_ptr++;
tty->flip.count++;
ignore_char:
tty_insert_flip_char(tty, ch, flag);
if (oe == 1)
tty_insert_flip_char(tty, 0, TTY_OVERRUN);
tty_flip_buffer_push(tty);
out:
return;
}
static _INLINE_ void transmit_chars(struct async_struct *info)
......
......@@ -641,6 +641,7 @@ static char rcsid[] =
#include <linux/timer.h>
#include <linux/interrupt.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial.h>
#include <linux/major.h>
#include <linux/string.h>
......@@ -1086,7 +1087,7 @@ cyy_interrupt(int irq, void *dev_id, struct pt_regs *regs)
int had_work;
int mdm_change;
int mdm_status;
int len;
if((cinfo = (struct cyclades_card *)dev_id) == 0){
#ifdef CY_DEBUG_INTERRUPTS
printk("cyy_interrupt: spurious interrupt %d\n\r", irq);
......@@ -1163,63 +1164,43 @@ cyy_interrupt(int irq, void *dev_id, struct pt_regs *regs)
info->icount.rx++;
continue;
}
if (tty->flip.count < TTY_FLIPBUF_SIZE){
tty->flip.count++;
if (tty_buffer_request_room(tty, 1)) {
if (data & info->read_status_mask){
if(data & CyBREAK){
*tty->flip.flag_buf_ptr++ =
TTY_BREAK;
*tty->flip.char_buf_ptr++ =
cy_readb(base_addr+(CyRDSR<<index));
tty_insert_flip_char(tty, cy_readb(base_addr+(CyRDSR<<index)), TTY_BREAK);
info->icount.rx++;
if (info->flags & ASYNC_SAK){
do_SAK(tty);
}
}else if(data & CyFRAME){
*tty->flip.flag_buf_ptr++ =
TTY_FRAME;
*tty->flip.char_buf_ptr++ =
cy_readb(base_addr+(CyRDSR<<index));
tty_insert_flip_char(tty, cy_readb(base_addr+(CyRDSR<<index)), TTY_FRAME);
info->icount.rx++;
info->idle_stats.frame_errs++;
}else if(data & CyPARITY){
*tty->flip.flag_buf_ptr++ =
TTY_PARITY;
*tty->flip.char_buf_ptr++ =
cy_readb(base_addr+(CyRDSR<<index));
/* Pieces of seven... */
tty_insert_flip_char(tty, cy_readb(base_addr+(CyRDSR<<index)), TTY_PARITY);
info->icount.rx++;
info->idle_stats.parity_errs++;
}else if(data & CyOVERRUN){
*tty->flip.flag_buf_ptr++ =
TTY_OVERRUN;
*tty->flip.char_buf_ptr++ = 0;
tty_insert_flip_char(tty, 0, TTY_OVERRUN);
info->icount.rx++;
/* If the flip buffer itself is
overflowing, we still lose
the next incoming character.
*/
if(tty->flip.count
< TTY_FLIPBUF_SIZE){
tty->flip.count++;
*tty->flip.flag_buf_ptr++ =
TTY_NORMAL;
*tty->flip.char_buf_ptr++ =
cy_readb(base_addr+(CyRDSR<<index));
info->icount.rx++;
}
tty_insert_flip_char(tty, cy_readb(base_addr+(CyRDSR<<index)), TTY_FRAME);
info->icount.rx++;
info->idle_stats.overruns++;
/* These two conditions may imply */
/* a normal read should be done. */
/* }else if(data & CyTIMEOUT){ */
/* }else if(data & CySPECHAR){ */
}else{
*tty->flip.flag_buf_ptr++ = 0;
*tty->flip.char_buf_ptr++ = 0;
info->icount.rx++;
}else {
tty_insert_flip_char(tty, 0, TTY_NORMAL);
info->icount.rx++;
}
}else{
*tty->flip.flag_buf_ptr++ = 0;
*tty->flip.char_buf_ptr++ = 0;
tty_insert_flip_char(tty, 0, TTY_NORMAL);
info->icount.rx++;
}
}else{
......@@ -1240,14 +1221,10 @@ cyy_interrupt(int irq, void *dev_id, struct pt_regs *regs)
info->mon.char_max = char_count;
info->mon.char_last = char_count;
#endif
while(char_count--){
if (tty->flip.count >= TTY_FLIPBUF_SIZE){
break;
}
tty->flip.count++;
len = tty_buffer_request_room(tty, char_count);
while(len--){
data = cy_readb(base_addr+(CyRDSR<<index));
*tty->flip.flag_buf_ptr++ = TTY_NORMAL;
*tty->flip.char_buf_ptr++ = data;
tty_insert_flip_char(tty, data, TTY_NORMAL);
info->idle_stats.recv_bytes++;
info->icount.rx++;
#ifdef CY_16Y_HACK
......@@ -1256,7 +1233,7 @@ cyy_interrupt(int irq, void *dev_id, struct pt_regs *regs)
}
info->idle_stats.recv_idle = jiffies;
}
schedule_delayed_work(&tty->flip.work, 1);
schedule_delayed_work(&tty->buf.work, 1);
}
/* end of service */
cy_writeb(base_addr+(CyRIR<<index), (save_xir & 0x3f));
......@@ -1551,6 +1528,7 @@ cyz_handle_rx(struct cyclades_port *info,
struct cyclades_card *cinfo = &cy_card[info->card];
struct tty_struct *tty = info->tty;
volatile int char_count;
int len;
#ifdef BLOCKMOVE
int small_count;
#else
......@@ -1606,18 +1584,11 @@ cyz_handle_rx(struct cyclades_port *info,
tty->flip.count += small_count;
}
#else
while(char_count--){
if (tty->flip.count >= N_TTY_BUF_SIZE - tty->read_cnt)
break;
if (tty->flip.count >= TTY_FLIPBUF_SIZE)
break;
len = tty_buffer_request_room(tty, char_count);
while(len--){
data = cy_readb(cinfo->base_addr + rx_bufaddr + new_rx_get);
new_rx_get = (new_rx_get + 1) & (rx_bufsize - 1);
tty->flip.count++;
*tty->flip.flag_buf_ptr++ = TTY_NORMAL;
*tty->flip.char_buf_ptr++ = data;
tty_insert_flip_char(tty, data, TTY_NORMAL);
info->idle_stats.recv_bytes++;
info->icount.rx++;
}
......@@ -1635,7 +1606,7 @@ cyz_handle_rx(struct cyclades_port *info,
}
#endif
info->idle_stats.recv_idle = jiffies;
schedule_delayed_work(&tty->flip.work, 1);
schedule_delayed_work(&tty->buf.work, 1);
}
/* Update rx_get */
cy_writel(&buf_ctrl->rx_get, new_rx_get);
......@@ -1763,23 +1734,17 @@ cyz_handle_cmd(struct cyclades_card *cinfo)
switch(cmd) {
case C_CM_PR_ERROR:
tty->flip.count++;
*tty->flip.flag_buf_ptr++ = TTY_PARITY;
*tty->flip.char_buf_ptr++ = 0;
tty_insert_flip_char(tty, 0, TTY_PARITY);
info->icount.rx++;
special_count++;
break;
case C_CM_FR_ERROR:
tty->flip.count++;
*tty->flip.flag_buf_ptr++ = TTY_FRAME;
*tty->flip.char_buf_ptr++ = 0;
tty_insert_flip_char(tty, 0, TTY_FRAME);
info->icount.rx++;
special_count++;
break;
case C_CM_RXBRK:
tty->flip.count++;
*tty->flip.flag_buf_ptr++ = TTY_BREAK;
*tty->flip.char_buf_ptr++ = 0;
tty_insert_flip_char(tty, 0, TTY_BREAK);
info->icount.rx++;
special_count++;
break;
......@@ -1844,7 +1809,7 @@ cyz_handle_cmd(struct cyclades_card *cinfo)
if(delta_count)
cy_sched_event(info, Cy_EVENT_DELTA_WAKEUP);
if(special_count)
schedule_delayed_work(&tty->flip.work, 1);
schedule_delayed_work(&tty->buf.work, 1);
}
}
......
......@@ -1786,9 +1786,7 @@ static void doevent(int crd)
if (tty) { /* Begin if valid tty */
if (event & BREAK_IND) { /* Begin if BREAK_IND */
/* A break has been indicated */
tty->flip.count++;
*tty->flip.flag_buf_ptr++ = TTY_BREAK;
*tty->flip.char_buf_ptr++ = 0;
tty_insert_flip_char(tty, 0, TTY_BREAK);
tty_schedule_flip(tty);
} else if (event & LOWTX_IND) { /* Begin LOWTX_IND */
if (ch->statusflags & LOWWAIT)
......@@ -2124,7 +2122,6 @@ static void receive_data(struct channel *ch)
int dataToRead, wrapgap, bytesAvailable;
unsigned int tail, head;
unsigned int wrapmask;
int rc;
/* ---------------------------------------------------------------
This routine is called by doint when a receive data event
......@@ -2162,16 +2159,15 @@ static void receive_data(struct channel *ch)
return;
}
if (tty->flip.count == TTY_FLIPBUF_SIZE)
if (tty_buffer_request_room(tty, bytesAvailable + 1) == 0)
return;
if (readb(&bc->orun)) {
writeb(0, &bc->orun);
printk(KERN_WARNING "epca; overrun! DigiBoard device %s\n",tty->name);
tty_insert_flip_char(tty, 0, TTY_OVERRUN);
}
rxwinon(ch);
rptr = tty->flip.char_buf_ptr;
rc = tty->flip.count;
while (bytesAvailable > 0) { /* Begin while there is data on the card */
wrapgap = (head >= tail) ? head - tail : ch->rxbufsize - tail;
/* ---------------------------------------------------------------
......@@ -2183,8 +2179,7 @@ static void receive_data(struct channel *ch)
/* --------------------------------------------------------------
Make sure we don't overflow the buffer
----------------------------------------------------------------- */
if ((rc + dataToRead) > TTY_FLIPBUF_SIZE)
dataToRead = TTY_FLIPBUF_SIZE - rc;
dataToRead = tty_prepare_flip_string(tty, &rptr, dataToRead);
if (dataToRead == 0)
break;
/* ---------------------------------------------------------------
......@@ -2192,13 +2187,9 @@ static void receive_data(struct channel *ch)
for translation if necessary.
------------------------------------------------------------------ */
memcpy_fromio(rptr, ch->rxptr + tail, dataToRead);
rc += dataToRead;
rptr += dataToRead;
tail = (tail + dataToRead) & wrapmask;
bytesAvailable -= dataToRead;
} /* End while there is data on the card */
tty->flip.count = rc;
tty->flip.char_buf_ptr = rptr;
globalwinon(ch);
writew(tail, &bc->rout);
/* Must be called with global data */
......
......@@ -345,26 +345,22 @@ static inline void receive_chars_pio(struct esp_struct *info, int num_bytes)
for (i = 0; i < num_bytes; i++) {
if (!(err_buf->data[i] & status_mask)) {
*(tty->flip.char_buf_ptr++) = pio_buf->data[i];
int flag = 0;
if (err_buf->data[i] & 0x04) {
*(tty->flip.flag_buf_ptr++) = TTY_BREAK;
flag = TTY_BREAK;
if (info->flags & ASYNC_SAK)
do_SAK(tty);
}
else if (err_buf->data[i] & 0x02)
*(tty->flip.flag_buf_ptr++) = TTY_FRAME;
flag = TTY_FRAME;
else if (err_buf->data[i] & 0x01)
*(tty->flip.flag_buf_ptr++) = TTY_PARITY;
else
*(tty->flip.flag_buf_ptr++) = 0;
tty->flip.count++;
flag = TTY_PARITY;
tty_insert_flip_char(tty, pio_buf->data[i], flag);
}
}
schedule_delayed_work(&tty->flip.work, 1);
schedule_delayed_work(&tty->buf.work, 1);
info->stat_flags &= ~ESP_STAT_RX_TIMEOUT;
release_pio_buffer(pio_buf);
......@@ -397,7 +393,6 @@ static inline void receive_chars_dma_done(struct esp_struct *info,
int num_bytes;
unsigned long flags;
flags=claim_dma_lock();
disable_dma(dma);
clear_dma_ff(dma);
......@@ -408,38 +403,31 @@ static inline void receive_chars_dma_done(struct esp_struct *info,
info->icount.rx += num_bytes;
memcpy(tty->flip.char_buf_ptr, dma_buffer, num_bytes);
tty->flip.char_buf_ptr += num_bytes;
tty->flip.count += num_bytes;
memset(tty->flip.flag_buf_ptr, 0, num_bytes);
tty->flip.flag_buf_ptr += num_bytes;
if (num_bytes > 0) {
tty->flip.flag_buf_ptr--;
tty_insert_flip_string(tty, dma_buffer, num_bytes - 1);
status &= (0x1c & info->read_status_mask);
/* Is the status significant or do we throw the last byte ? */
if (!(status & info->ignore_status_mask)) {
int statflag = 0;
if (status & info->ignore_status_mask) {
tty->flip.count--;
tty->flip.char_buf_ptr--;
tty->flip.flag_buf_ptr--;
} else if (status & 0x10) {
*tty->flip.flag_buf_ptr = TTY_BREAK;
(info->icount.brk)++;
if (info->flags & ASYNC_SAK)
do_SAK(tty);
} else if (status & 0x08) {
*tty->flip.flag_buf_ptr = TTY_FRAME;
(info->icount.frame)++;
}
else if (status & 0x04) {
*tty->flip.flag_buf_ptr = TTY_PARITY;
(info->icount.parity)++;
if (status & 0x10) {
statflag = TTY_BREAK;
(info->icount.brk)++;
if (info->flags & ASYNC_SAK)
do_SAK(tty);
} else if (status & 0x08) {
statflag = TTY_FRAME;
(info->icount.frame)++;
}
else if (status & 0x04) {
statflag = TTY_PARITY;
(info->icount.parity)++;
}
tty_insert_flip_char(tty, dma_buffer[num_bytes - 1], statflag);
}
tty->flip.flag_buf_ptr++;
schedule_delayed_work(&tty->flip.work, 1);
schedule_delayed_work(&tty->buf.work, 1);
}
if (dma_bytes != num_bytes) {
......@@ -693,8 +681,7 @@ static irqreturn_t rs_interrupt_single(int irq, void *dev_id,
num_bytes = serial_in(info, UART_ESI_STAT1) << 8;
num_bytes |= serial_in(info, UART_ESI_STAT2);
if (num_bytes > (TTY_FLIPBUF_SIZE - info->tty->flip.count))
num_bytes = TTY_FLIPBUF_SIZE - info->tty->flip.count;
num_bytes = tty_buffer_request_room(info->tty, num_bytes);
if (num_bytes) {
if (dma_bytes ||
......
......@@ -597,9 +597,7 @@ static int hvc_poll(struct hvc_struct *hp)
/* Read data if any */
for (;;) {
int count = N_INBUF;
if (count > (TTY_FLIPBUF_SIZE - tty->flip.count))
count = TTY_FLIPBUF_SIZE - tty->flip.count;
int count = tty_buffer_request_room(tty, N_INBUF);
/* If flip is full, just reschedule a later read */
if (count == 0) {
......@@ -635,7 +633,7 @@ static int hvc_poll(struct hvc_struct *hp)
tty_insert_flip_char(tty, buf[i], 0);
}
if (tty->flip.count)
if (count)
tty_schedule_flip(tty);
/*
......
......@@ -456,12 +456,11 @@ static int hvcs_io(struct hvcs_struct *hvcsd)
/* remove the read masks */
hvcsd->todo_mask &= ~(HVCS_READ_MASK);
if ((tty->flip.count + HVCS_BUFF_LEN) < TTY_FLIPBUF_SIZE) {
if (tty_buffer_request_room(tty, HVCS_BUFF_LEN) >= HVCS_BUFF_LEN) {
got = hvc_get_chars(unit_address,
&buf[0],
HVCS_BUFF_LEN);
for (i=0;got && i<got;i++)
tty_insert_flip_char(tty, buf[i], TTY_NORMAL);
tty_insert_flip_string(tty, buf, got);
}
/* Give the TTY time to process the data we just sent. */
......@@ -469,10 +468,9 @@ static int hvcs_io(struct hvcs_struct *hvcsd)
hvcsd->todo_mask |= HVCS_QUICK_READ;
spin_unlock_irqrestore(&hvcsd->lock, flags);
if (tty->flip.count) {
/* This is synch because tty->low_latency == 1 */
/* This is synch because tty->low_latency == 1 */
if(got)
tty_flip_buffer_push(tty);
}
if (!got) {
/* Do this _after_ the flip_buffer_push */
......
......@@ -115,6 +115,7 @@
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/termios.h>
#include <linux/fs.h>
#include <linux/sched.h>
......@@ -773,6 +774,7 @@ static irqreturn_t isicom_interrupt(int irq, void *dev_id,
unsigned short base, header, word_count, count;
unsigned char channel;
short byte_count;
unsigned char *rp;
card = (struct isi_board *) dev_id;
......@@ -903,14 +905,10 @@ static irqreturn_t isicom_interrupt(int irq, void *dev_id,
break;
case 1: /* Received Break !!! */
if (tty->flip.count >= TTY_FLIPBUF_SIZE)
break;
*tty->flip.flag_buf_ptr++ = TTY_BREAK;
*tty->flip.char_buf_ptr++ = 0;
tty->flip.count++;
tty_insert_flip_char(tty, 0, TTY_BREAK);
if (port->flags & ASYNC_SAK)
do_SAK(tty);
schedule_delayed_work(&tty->flip.work, 1);
tty_flip_buffer_push(tty);
break;
case 2: /* Statistics */
......@@ -923,23 +921,19 @@ static irqreturn_t isicom_interrupt(int irq, void *dev_id,
}
}
else { /* Data Packet */
count = min_t(unsigned short, byte_count, (TTY_FLIPBUF_SIZE - tty->flip.count));
count = tty_prepare_flip_string(tty, &rp, byte_count & ~1);
#ifdef ISICOM_DEBUG
printk(KERN_DEBUG "ISICOM: Intr: Can rx %d of %d bytes.\n",
count, byte_count);
#endif
word_count = count >> 1;
insw(base, tty->flip.char_buf_ptr, word_count);
tty->flip.char_buf_ptr += (word_count << 1);
insw(base, rp, word_count);
byte_count -= (word_count << 1);
if (count & 0x0001) {
*tty->flip.char_buf_ptr++ = (char)(inw(base) & 0xff);
tty_insert_flip_char(tty, inw(base) & 0xff, TTY_NORMAL);
byte_count -= 2;
}
memset(tty->flip.flag_buf_ptr, 0, count);
tty->flip.flag_buf_ptr += count;
tty->flip.count += count;
if (byte_count > 0) {
printk(KERN_DEBUG "ISICOM: Intr(0x%x:%d): Flip buffer overflow! dropping bytes...\n",
base, channel+1);
......@@ -948,7 +942,7 @@ static irqreturn_t isicom_interrupt(int irq, void *dev_id,
byte_count -= 2;
}
}
schedule_delayed_work(&tty->flip.work, 1);
tty_flip_buffer_push(tty);
}
if (card->isa == YES)
ClearInterrupt(base);
......
......@@ -2711,17 +2711,13 @@ static void stli_read(stlibrd_t *brdp, stliport_t *portp)
stlen = size - tail;
}
len = MIN(len, (TTY_FLIPBUF_SIZE - tty->flip.count));
len = tty_buffer_request_room(tty, len);
/* FIXME : iomap ? */
shbuf = (volatile char *) EBRDGETMEMPTR(brdp, portp->rxoffset);
while (len > 0) {
stlen = MIN(len, stlen);
memcpy(tty->flip.char_buf_ptr, (char *) (shbuf + tail), stlen);
memset(tty->flip.flag_buf_ptr, 0, stlen);
tty->flip.char_buf_ptr += stlen;
tty->flip.flag_buf_ptr += stlen;
tty->flip.count += stlen;
tty_insert_flip_string(tty, (char *)(shbuf + tail), stlen);
len -= stlen;
tail += stlen;
if (tail >= size) {
......@@ -2906,16 +2902,12 @@ static int stli_hostcmd(stlibrd_t *brdp, stliport_t *portp)
if ((nt.data & DT_RXBREAK) && (portp->rxmarkmsk & BRKINT)) {
if (tty != (struct tty_struct *) NULL) {
if (tty->flip.count < TTY_FLIPBUF_SIZE) {
tty->flip.count++;
*tty->flip.flag_buf_ptr++ = TTY_BREAK;
*tty->flip.char_buf_ptr++ = 0;
if (portp->flags & ASYNC_SAK) {
do_SAK(tty);
EBRDENABLE(brdp);
}
tty_schedule_flip(tty);
tty_insert_flip_char(tty, 0, TTY_BREAK);